Why is this error ":OperationStopped: Optional.Value expects values of type" happening in powershell

Question

I am trying to use VMware PowerCLI (installed on powershell running in MAC) to create a static route with next-hop address. I am getting this error when

I am using the below patch method to create this static route and i am getting this error (Optional.Value expects values of type) when running this command although i have correctly formed other parameters for this. Not sure why this is happening and any help would be much appreciated. thanks.

**PS /Users/r>  $S3.patch('Router_Demo','10.118.11.37/32',$Rspec)**        
OperationStopped: Optional.Value expects values of type  'System.Collections.Generic.List`1[[System.Management.Automation.PSObject, System.Management.Automation, Version=7.2.1.500, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]' but received value of type 'System.Management.Automation.PSObject'.



**PS /Users/r> $S3**

Name
----
com.vmware.nsx_policy.infra.tier_1s.static_routes


**PS /Users/r> $S3 | Get-Member**

   TypeName: VMware.VimAutomation.Cis.Core.Impl.V1.CisServiceBase

Name          MemberType     Definition
----          ----------     ----------
delete        CodeMethod     void delete(string tier1_id, string route_id)
get           CodeMethod     com.vmware.nsx_policy.model.static_routes get(string tier1_id, string route_id)
list          CodeMethod     com.vmware.nsx_policy.model.static_routes_list_result list(string tier1_id, string? cursor, boolean? include_mark_for_delete_objects, string? included_fields, long? page_size, boolean? sort_ascending, string? sort_by)
**patch         CodeMethod     void patch(string tier1_id, string route_id, com.vmware.nsx_policy.model.static_routes static_routes)**
update        CodeMethod     com.vmware.nsx_policy.model.static_routes update(string tier1_id, string route_id, com.vmware.nsx_policy.model.static_routes static_routes)
Equals        Method         bool Equals(System.Object obj)
GetHashCode   Method         int GetHashCode()
GetType       Method         type GetType()
ToString      Method         string ToString()
Constants     NoteProperty   System.Management.Automation.PSCustomObject Constants=
Documentation NoteProperty   string Documentation=
_help_cache   NoteProperty   Lazy[psobject] _help_cache=@{Documentation=; Constants=System.Collections.Generic.List`1[System.Management.Automation.PSObject]; patch=; get=; update=; list=; delete=}
Name          Property       string Name {get;}
Uid           Property       string Uid {get;}
Help          ScriptProperty System.Object Help {get=$this._help_cache.Value;}

**PS /Users/r> $Rspec**

self                 : <Unset, [com.vmware.nsx_policy.model.self_resource_link]>
revision             : <Unset, [long]>
description          : <Unset, [string]>
display_name         : Test-VM
id                   : <Unset, [string]>
resource_type        : <Unset, [string]>
tags                 : <Unset, [List<com.vmware.nsx_policy.model.tag>]>
children             : <Unset, [List<dynamic_structure>]>
enabled_on_secondary : <Unset, [boolean]>
network              : 10.118.10.37/32
next_hops            : @{admin_distance=1; ip_address=10.130.130.2; scope=none}


**PS /Users/r> $Nhopspec**         

admin_distance ip_address   scope
-------------- ----------   -----
    1 10.130.130.2 none

Thanks